Studies show substantial benefit to reduce morbidity and excess mortality for people living with HIV (PLWH) who adhere to antiretroviral therapy (ART), and to lower the probability of forward transmission to sexual partners. Despite efforts to maintain engagement of PLWH along the treatment cascade, it is estimated that only 19-25%% of PLWH and 27% of MSM in the US maintain suppressed viral load (VL). Several technology- based ART adherence interventions have demonstrated efficacy, however all have been individually delivered and have failed to leverage Web 2.0 features. While peer-to-peer social support is a recommended strategy to improve ART adherence and has enormous immediate appeal as a generalizable intervention approach, no peer-to-peer social support ART adherence interventions have been tested in a full-scale efficacy trial. The Thrive with Me (TWM) intervention is a technology-delivered peer-to-peer social support intervention grounded in the Information, Motivation, and Behavioral Skills (IMB) model for HIV-positive MSM. In addition to asynchronous peer-to-peer support capabilities, the TWM intervention provides participants with ART adherence self-monitoring tools, medication dose reminders, and HIV-related informational content. A pilot study of the TWM intervention demonstrated feasibility and acceptability of this approach; results showed that the TWM intervention group self-reported improvement in adherence at follow-up compared to the usual care control group, with greatest gains evident among recent drug users. Based on the encouraging findings of TWM study and the need for novel, evidence-based effective ART adherence interventions, we propose the following study aims. Primary aims (Aims 1 and 2) are to examine the efficacy of the online and mobile- enabled TWM intervention in a full-scale randomized controlled trial. HIV-positive MSM with detectable VL residing in New York City will be randomized to receive the TWM intervention or an information-only HIV/ART intervention for a 5-month period. Recruitment will be stratified by recent drug use, such that half will report recent illicit drug use. VL, validated self-reported AR adherence, and intervention utilization measures will be collected at baseline, post-intervention, and 5-, and 10-month follow up. We hypothesize that participants in the TWM intervention will demonstrate significant improvements in self-reported ART adherence and VL at each follow-up time point compared to control participants, with greatest improvements among recent drug users. Aim 3 (a secondary aim) is to examine the effects of the intervention on theory-based change processes (i.e., IMB factors and social support) for improving VL, ART adherence, and substance use outcomes. The proposal is innovative for its use of mobile and online technology as an ART adherence intervention delivery tool, and for being the first technology-delivered peer-to-peer support ART adherence intervention. The public health significance of the proposed study is that it advances ART adherence intervention for persons in greatest need of intervention and, if effective, may be quickly scaled up for dissemination.